title: Identification of nonclonal Pseudomonas aeruginosa isolates with reduced colistin susceptibility in Korea.
abstract: The in vitro activity of colistin was evaluated against 215 nonduplicated Pseudomonas aeruginosa isolates, including 53 multidrug-resistant isolates, which were collected between 2006 and 2007 from nine tertiary care hospitals in Korea. Colistin-nonsusceptible P. aeruginosa (CNPA) isolates were genotyped using multilocus sequence typing. Sixteen (7.4%) CNPA isolates (minimum inhibitory concentration [MIC], >2 mg/l) were identified, including three resistant isolates. All but one of the MDR P. aeruginosa isolates was susceptible to colistin. Multilocus sequence typing analysis identified 12 sequence types (STs) among 16 CNPA isolates, indicating that colistin nonsusceptibility might arise independently. However, ST244 and ST292, which may be international clones, were found in multiple CNPA isolates. Our data indicate an increase of P. aeruginosa isolates with reduced colistin susceptibility, suggesting the need for continuous surveillance of P. aeruginosa.
authors.affiliation: Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, South Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Song
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Ko
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D003091:Colistin / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics*; D006786:Hospitals, Urban; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D011552:Pseudomonas Infections / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology* / Q000652:urine; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D056910:Republic of Korea
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin